Process for coloring high-molecular weight organic material using amine salts of azo pigments based on pyrazolone derivatives

ABSTRACT

Compounds of formula ##STR1## wherein a and b are each independently of the other halogen, --CH 3 , --C 2  H 5 , --OCH 3 , --OC 2  H 5  or the group of formula --NHCO--C 1  -C 4  alkyl, c and d are each independently of the other hydrogen, halogen, --CH 3 , --C 2  H 5 , --OCH 3 , --OC 2  H 5  or the group of formula --NHCO--C 1  -C 4  alkyl, and R 1  is --CH 3 , phenyl, --COOCH 3 , --COOC 2  H 5 , --NHCO--C 1  -C 4  alkyl or --CONH--C 1  -C 4  alkyl, and R 2 , R 3 , R 4  and R 5  are each independently hydrogen, C 1  -C 4  alkyl, unsubstituted or substituted by a chlorine atom or a --OH group, or are C 7  -C 9  aralkyl, C 5  -C 8  cycloalkyl, phenyl or phenyl which is substituted by 1 to 3 halogen atoms or methyl or methoxy groups, or is a heterocyclic radical of the benzimidazole, benzoxazole, benzthiazole or pyridine series, or R 3  and R 4 , together with the linking nitrogen atom, are a pyrrolidine, imidazolidine, piperidine, piperazine or morpholine radical, or R 3 , R 4  and R 5 , together with the linking nitrogen atom, are a pyrrole, pyridine, picoline, pyrazine, quinoline or isoquinoline radical, are most suitable for coloring high molecular organic material.

This is a continuation of application Ser. No. 020,059, filed on Feb.27, 1987, now abandoned.

The present invention relates to novel amine salts of azo compounds, tothe preparation thereof, and to the use thereof for colouring highmolecular organic material.

Amine salts of azo compounds are known in the art. Thus, for example,ammonium salts of sulfonated azo dyes of the pyrazolone series aredisclosed in European patent application 0 073 972. Such compounds areused as pigments for colouring plastics materials.

Specifically, the present invention relates to compounds of formula##STR2## wherein a and b are each independently of the other halogen,--CH₃, --C₂ H₅, --OCH₃, --OC₂ H₅ or the group of formula --NHCO--C₁ -C₄alkyl, c and d are each independently of the other hydrogen, halogen,--CH₃, --C₂ H₅, --OCH₃, --OC₂ H₅ or the group of formula --NHCO--C₁ -C₄alkyl, and R¹ is --CH₃, phenyl, --COOCH₃, --COOC₂ H₅, --NHCO--C₁ -C₄alkyl or --CONH--C₁ -C₄ alkyl, and R², R³, R⁴ and R⁵ are eachindependently hydrogen, C₁ -C₄ alkyl, unsubstituted or substituted by achlorine atom or a --OH group, or are C₇ -C₉ aralkyl, C₅ -C₈ cycloalkyl,phenyl or phenyl which is substituted by 1 to 3 halogen atoms or methylor methoxy groups, or is a heterocyclic radical of the benzimidazole,benzoxazole, benzthiazole or pyridine series, or R³ and R⁴, togetherwith the linking nitrogen atom, are a pyrrolidine, imidazolidine,piperidine, piperazine or morpholine radical, or R³, R⁴ and R⁵, togetherwith the linking nitrogen atom, are a pyrrole, pyridine, picoline,pyrazine, quinoline or isoquinoline radical.

The C₁ -C₄ alkyl moiety of --NHCO--C₁ -C₄ alkyl and --CONH--C₁ -C₄ alkylradicals may be methyl, ethyl, n-propyl, isopropyl, n-butyl andtert-butyl, with methyl being preferred.

Halogen by itself as a, b, c and d and as substituent R², R³, R⁴ and R⁵of phenyl is fluorine, chlorine, bromine or iodine, with chlorine orbromine being preferred and chlorine most preferred.

R², R³, R⁴ and R⁵ as C₁ -C₄ alkyl may be methyl, ethyl, n-propyl,isopropyl, n-butyl and tert-butyl.

C₁ -C₄ Alkyl substituted by a chlorine atom or a --OH group may beβ-chloroethyl or 2-hydroxyethyl.

R², R³, R⁴ and R⁵ as C₇ -C₉ aralkyl may be benzyl or ethylphenyl.

C₅ -C₈ Cycloalkyl may be cyclopentyl, cyclohexyl, cycloheptyl orcyclooctyl.

Heterocyclic radicals of the benzimidazole, benzoxazole, benzthiazoleand pyridine series are e.g. radicals derived from 5-aminobenzimidazole,5-amino-2-methylbenzimidazole, 5-aminobenzoxazole, 5-aminobenzthiazole,2-amino-6-ethoxybenzthiazole, 2-aminobenzimidazole, and 2-, 3- or4-aminopyridine.

Particularly preferred compounds of formula I are those wherein a and bare each independently of the other --Cl, --Br, --CH₃ or --OCH₃, c and dare each independently of the other hydrogen, --Cl, --Br, --CH₃ or--OCH₃, R¹ is --CH₃, --COOC₂ H₅, --CONHCH₃ or --NHCOCH₃, and R², R³, R⁴and R⁵ are each independently hydrogen or --CH₃.

The most preferred compounds of formula I are those wherein a and b areeach independently of the other --Cl or --CH₃, c and d are eachindependently of the other hydrogen, --Cl or --CH₃, R¹ is --CH₃ and R²,R³, R⁴ and R⁵ are hydrogen.

The compounds of formula I are prepared, for example, by reacting adiazo compound of an amine of formula II ##STR3## with a couplingcomponent of formula III ##STR4## under reactions which are known perse, and subsequently treating the reaction product, which is preferablyin the form of the free disulfonic acid, with a compound of formula IV

    N.sup.⊕ (R.sup.2)(R.sup.3)(R.sup.4)(R.sup.5)           (IV)

in the form of its chloride or sulfate, in which formulae II, III and IVabove a, b, c, d, R¹ and R² to R⁵ are as defined above.

Instead of the chloride or sulfate of this compound, it is also possibleto use the free compound.

A variant of the process comprises carrying out the diazotisation andcoupling steps without using an inorganic acid by mixing the amine offormula II and the coupling component of formula III, in water or in anorganic solvent, with the stoichiometric amount of a nitrite, e.g.NaNO₂, and converting the resultant azo compound into the compound offormula I by conventional methods.

Examples of amines of formula II are:2-amino-3-methyl-5-chlorobenzenesulfonic acid,2-amino-3,4-dichlorobenzenesulfonic acid,2-amino-3,5-dichlorobenzenesulfonic acid,2-amino-3,5-dimethylbenzenesulfonic acid,2-amino-4,5-dimethylbenzenesulfonic acid,2-amino-4-chloro-5-acetylaminobenzenesulfonic acid,2-amino-4-methoxy-5-acetylaminobenzenesulfonic acid,2-amino-4-chloro-5-methylbenzenesulfonic acid,2-amino-4-methyl-5-chlorobenzenesulfonic acid,2-amino-4,5-dichlorobenzenesulfonic acid,2-amino-4-chloro-5-methoxybenzenesulfonic acid.

Examples of coupling components of formula III are:

1-(2'-sulfophenyl)-3-methyl-5-pyrazolone;

1-(4',5'-dichloro-2'-sulfophenyl)-3-methyl-5-pyrazolone,

1-(3'-sulfophenyl)-3-methyl-5-pyrazolone,

1-(6'-chloro-3'-sulfophenyl)-3-methyl-5-pyrazolone,

1-(4'-sulfophenyl)-3-methyl-5-pyrazolone,

1(2'-chloro-6'-methyl-4'-sulfophenyl)-3-methyl-5-pyrazolone,

1-(2'-methyl-4'-sulfophenyl)-3-methylpyrazolone,

1-(2',5'dichloro-4'-sulfophenyl)-3-methylpyrazolone,

1-(3'-sulfophenyl)-3-carbomethoxy-5-pyrazolone,

1-(2',5,-dichloro-4'-sulfophenyl)-3-carbomethoxy-5-pyrazolone,

1-(3'-sulfophenyl)-3-carboethoxy-5-pyrazolone,

1-(2',5'-dichloro-4'-sulfophenyl)-3-carboethoxy-5-pyrazolone,

1-(3'-sulfophenyl)-3-(N-methylcarbamyl)-5-pyrazolone,

1-(3'-sulfophenyl)-3-acetylamino-5-pyrazolone,

1-(2',5'-dichloro-4'-sulfophenyl)-3-acetylamino-5-pyrazolone.

Examples of free compounds of formula IV are: ammonia, methylamine,ethylamine, n-propylamine, n-butylamine, cyclohexylamine, benzylamine,aniline, 2-chloroaniline, 2-, 3- or 4-methylaniline,2,4-dimethylaniline, 2,4,6-trimethylaniline, dimethylamine,trimethylamine, tetramethylamine, 2-, 3- or 4-aminopyridine, morpholine,piperidine, 2-, 3- or 4-picoline as well as pyridine.

The compounds of formula I can be used as pigments for colouring highmolecular organic material. They can normally be used direct in the formin which they are obtained in their synthesis. Depending on theenvisaged utility, the compounds of formula I can be converted into amore opaque or more transparent form.

If it is desired to obtain a more opaque pigment form, then it isusually expedient to effect a thermal aftertreatment in water or anorganic solvent, under normal or elevated pressure. It is preferred touse organic solvents such as benzenes which are substituted by halogenatoms, alkyl or nitro groups, for example xylenes, chlorobenzene,o-dichlorobenzene or nitrobenzene, as well as pyridine bases such aspyridine, picoline or quinoline, and also ketones such as cyclohexanone,alcohols such as isopropanol, butanols or pentanols, ethers such asethylene glycol monomethyl or monoethyl ether, amides such asdimethylformamide or N-methylpyrrolidone, as well as dimethylsulfoxideor sulfolane. The aftertreatment can also be carried out in water, undernormal or elevated pressure, in the presence of organic solvents and/orwith the addition of surfactants.

Examples of high molecular organic materials which may be coloured withthe compounds of formula I are cellulose ethers and esters such as ethylcellulose, nitrocellulose, cellulose acetate, cellulose butyrate,natural resins or synthetic resins such as polymerisation resins orcondensation resins, for example aminoplasts, in particularurea/formaldehyde and melamine/formaldehyde resins, alkyd resins,phenolic plastics, polycarbonates, polyolefins, polystyrene, polyvinylchloride, polyamides, polyurethanes, polyesters, rubber, casein,silicone and silicone resins, singly or in mixtures.

The compounds of formula I are particularly suitable for colouringpolyvinyl chloride and polyolefins such as polyethylene andpolypropylene.

The above high molecular organic compounds may be singly or as mixturesin the form of plastics, melts or of spinning solutions, varnishes,paints or printing inks. Depending on the utility, it is advantageous touse the compounds of formula I as toners or in the form of preparations.

The compounds of formula I are preferably employed in an amount of 0.01to 30% by weight, preferably 0.1 to 10% by weight, based on the highmolecular organic material to be pigmented.

The pigmenting of the high molecular organic compounds with thecompounds of formula I is carried out for example by incorporating sucha compound, optionally in the form of a masterbatch, into the substratesusing roll mills, mixing or grinding machines. The pigmented material isthen brought into the desired final form by methods which are known perse, for example calendering, moulding, extruding, coating, spinning,casting or by injection moulding. It is often desirable to incorporateplasticisers into the high molecular compounds before processing inorder to produce non-brittle mouldings or to diminish their brittleness.Suitable plasticisers are for example esters of phosphoric acid,phthalic acid or sebacic acid. The plasticisers may be incorporatedbefore or after working the compound of formula I into the polymers. Toobtain different shades, it is also possible to add fillers or otherchromophoric components such as white, coloured or black pigments, inany amount, to the high molecular organic compounds, in addition to thecompounds of formula I.

For pigmenting varnishes and printing inks, the high molecular organicmaterials and the compounds of formula I, together with optionaladditives such as fillers, other pigments, siccatives or plasticisers,are finely dispersed or dissolved in a common organic solvent or mixtureof solvents. The procedure may be such that the individual components bythemselves, or also several jointly, are dispersed or dissolved in thesolvent and subsequently all the components are mixed.

The colourations obtained, for example, in polyvinyl chloride orpolyolefins with the compounds of formula I, have good allround fastnessproperties such as good dispersibility, high tinting strength andpurity, good fastness to migration, heat, light, and weathering, as wellas good hiding power.

In the following Examples, parts and percentages are by weight.

EXAMPLE 1

5.2 g of the azo compound of the formula ##STR5## (obtainable by knownmethods) are dissolved at room temperature in a mixture of 50 ml ofacetic acid and 50 ml of deionized water. To the clear, dark redsolution is added, over 2 minutes, a solution of 2.6 g of anilinehydrochloride in 10 ml of distilled water. The resultant orange yellowsuspension is stirred for 3 hours at room temperature and filtered. Thefilter residue is washed with 100 ml of deionised water and vacuum driedat 60° C., affording 5.1 g of a deep orange powder of formula ##STR6##

Analysis: theory (in %): C 48.49, H 3.78; Cl 10.22; N 12.11; S 9.24;found (in %): C 48.32; H 3.87; Cl 10.46; N 12.20; S 8.90.

This compound colours polyvinyl chloride and polyethylene in strong,fast yellow shades.

Instead of using aniline hydrochloride, it is possible to use otheramine hydrochlorides listed in the following table to give the compoundsof formula ##STR7## in accordance with the process conditions describedin this Example.

    __________________________________________________________________________                                          Shade in                                                                      soft PVC                                                                      (0.2% of                                Example                                                                            Amine hydrochloride                                                                          A                 pigment)                                __________________________________________________________________________    2    ammonium chloride                                                                            .sup.⊕NH.sub.4                                                                              yellow                                  3    methylamine hydrochloride                                                                    H.sub.3.sup.⊕NCH.sub.3                                                                      orange                                                                        yellow                                  4    benzylamine hydrochloride                                                                    H.sub.3.sup.⊕NCH.sub.2 C.sub.6 H.sub.5                                                      yellow                                  5    trimethylamine hydrochloride                                                                 H.sup.⊕N(CH.sub.3).sub.3                                                                    yellow                                  6    tetramethylammonium chloride                                                                 .sup.⊕N(CH.sub.3).sub.4                                                                     greenish                                                                      yellow                                  7    2,5-dimethylaniline hydro- chloride                                                           ##STR8##         yellow                                  8    pyridine hydrochloride                                                                        ##STR9##         yellow                                  9    2-hydroxyethyl hydrochloride                                                                 H.sub.3.sup.⊕NCH.sub.2 CH.sub.2OH                                                           yellow                                  10   cyclohexylamine hydrochloride                                                                 ##STR10##        yellow                                  11   morpholine hydrochloride                                                                      ##STR11##        yellow                                  12   2-aminopyridine hydrochloride                                                                 ##STR12##        yellow                                  13   6-amino-benzthiazole hydro- chloride                                                          ##STR13##        yellow                                  14   5-amino-2-methylbenz- imidazole hydrochloride                                                 ##STR14##        yellow                                  __________________________________________________________________________

EXAMPLE 15

15.4 g of 36% disodium salt of the azo compound used in Example 1 and4.4 g of ammonium chloride are heated to 80° C. in 100 ml of deionizedwater. The deep yellow suspension is stirred for 4 hours at thistemperature, cooled to room temperature and filtered. The filter residueis washed with a small amount of deionised water and vacuum dried at 60°C., affording 5.1 g (94.2% of theory) of a product that is identicalstructurally and in all properties with the pigment obtained in Example2. In analogous manner, further compounds of formula I can be preparedstarting from an amine of formula II, a coupling component of formulaIII and an amine of formula IV, as listed in the following table.

    __________________________________________________________________________                                          Shade in                                                                 Amine of                                                                           soft PVC                                Ex- Amine of      Coupling component                                                                           formula                                                                            (0.2% of                                ample                                                                             formula II    of formula III IV   pigment)                                __________________________________________________________________________    16                                                                                 ##STR15##                                                                                   ##STR16##     NH.sub.3                                                                           yellowish orange                        17                                                                                 ##STR17##                                                                                   ##STR18##     CH.sub.3 NH.sub.2                                                                  yellowish orange                        18                                                                                 ##STR19##                                                                                   ##STR20##     NH.sub.3                                                                           yellow                                  19                                                                                 ##STR21##                                                                                   ##STR22##     CH.sub.3 NH.sub.2                                                                  yellow                                  20                                                                                 ##STR23##                                                                                   ##STR24##     NH.sub.3                                                                           orange yellow                           21                                                                                 ##STR25##                                                                                   ##STR26##     NH.sub.3                                                                           orange yellow                           22                                                                                 ##STR27##                                                                                   ##STR28##     NH.sub.3                                                                           orange                                  23                                                                                 ##STR29##                                                                                   ##STR30##     NH.sub.3                                                                           yellow                                  24                                                                                 ##STR31##                                                                                   ##STR32##     NH.sub.3                                                                           greenish yellow                         25                                                                                 ##STR33##                                                                                   ##STR34##     NH.sub.3                                                                           greenish yellow                         26                                                                                 ##STR35##                                                                                   ##STR36##     NH.sub.3                                                                           greenish yellow                         27                                                                                 ##STR37##                                                                                   ##STR38##     NH.sub.3                                                                           greenish yellow                         28                                                                                 ##STR39##                                                                                   ##STR40##     NH.sub.3                                                                           greenish yellow                         29                                                                                 ##STR41##                                                                                   ##STR42##     NH.sub.3                                                                           yellow                                  30                                                                                 ##STR43##                                                                                   ##STR44##     CH.sub.3 NH.sub.2                                                                  orange                                  31                                                                                 ##STR45##                                                                                   ##STR46##     NH.sub.3                                                                           yellow                                  __________________________________________________________________________

EXAMPLE 32

13 g of 93% 2-amino-4,5-dichlorobenzenesulfonic acid are dissolved in 90ml of deionised water and 5.7 ml of 25% ammonia solution. Then 27.5 mlof 23.5% hydrochloric acid are added to the clear, reddish violetsolution. The resultant thick, white suspension is cooled to 5° C. and12.5 ml of 4 N sodium nitrite solution are then added over 5 minutes.Then 15.5 g of 90.1% 1-(3'-sulfophenyl)-3-methyl-5-pyrazolone in theform of a fine suspension in 100 ml of deionised water are addeddropwide over 5 minutes to the slightly beige-coloured suspension. ThepH of the resultant pale yellow suspension is adjusted to 6.5 with 15.5ml of 25% ammonia solution. The now orange-coloured suspension isstirred for 3 hours, during which time the temperature of the suspensionrises from 5° to 22° C. When coupling is complete, this suspension isheated to 80° C., stirred for 6 hours at this temperature, then cooledto room temperature and filtered. The filter residue is washed with asmall amount of deionised water and vacuum dried at 60° C., affording26.9 g (99.5% of theory) of a product which is identical with that ofExample 2.

EXAMPLE 33

5.2 g of the azo compound used in Example 1 (disulfonic acid) aredissolved at 70° C. in 150 ml of deionised water. Then 1.85 g of anilineare added to the clear, red solution. The resultant orange suspension isstirred for 2 hours without heating and then filtered. The residue iswashed with 100 ml of deionised water and vacuum dried at 60° C.,affording 5.6 g (80.8% of theory) of an orange product that is identicalin structure and all properties with the pigment obtained in Example 1.

What is claimed is:
 1. A process for mass coloring high molecular weightorganic material selected from the group consisting of cellulose ethers,cellulose esters, aminoplasts, alkyd resins, phenolic plastics,polycarbonates, polyolefins, polystyrene, poly(vinyl chloride),polyamides, polyurethanes, polyesters, rubber, casein, silicone resinsand mixtures thereof, which process comprisesincorporating into saidorganic material an effective coloring amount of a pigment of formula I##STR47## wherein a and b are each --Cl,c and d are each independentlyof the other hydrogen, --Cl or --CH₃, R¹ is --CH₃, and R², R³, R⁴ and R⁵are each hydrogen.
 2. A process according to claim 1 where the pigmentof formula I, c and d are each hydrogen.
 3. A process according to claim1 wherein the high molecular weight organic material is poly(vinylchloride) or polyolefin.
 4. A high molecular weight material coloredaccording to the process of claim 1.